聲源在空氣中運(yùn)動(dòng),前方波被擠短,后方波被拉伸,是1842年奧地利物理學(xué)家約翰.克里琴斯.多普勒首先提出.此為多普勒效應(yīng),一般人并不陌生.鴨子在平靜水面嬉戲,泛起圈圈圓波勻速向遠(yuǎn)處擴(kuò)散.鴨子游弋,因與前方波同向,與后方波反向運(yùn)動(dòng),前后方波幅就發(fā)生了變化,鴨子也偏離了圓的中心
With an observer stationary relative to the medium,if a moving source is emitting waves with an actual frequency (in this case,the wavelength is changed,the transmission velocity of the wave keeps constant note that the transmission velocity of the wave does not depend on the velocity of the source),then the observer detects waves with a frequency given by
